6、. Theheartofanelectroniccomputerliesinitsvacuumtubes,or(16).Itselectroniccircuitsworkathousandtimesfasterthanthenervecellsinthehumanbrain.Aproblemthatmighttakeahumanbeingtwoyearstosolvecanbesolvedbyacomputerinoneminute,butinordertowork(17) ,acomputermustbegiven(18) --itmustbeprogrammed. Co